Esters of endo-methylene hexahydrophthalic acids with higher aliphatic alcohols



Patented Feb. 16, 1943 ESTERS OF ENDO-1WETHYL13NE HEXAHY- DROPHTHALICACIDS WITH HIGHER ALIPHATIC ALCOHOLS Charles E. Stafl', Charleston, w.va, assignor to Carbide and Carbon Chemicals Corporation, a

corporation of New York No Drawing. Application October 18, 1941,SerialN 415,633

3 Claims.

This application is a continuation-in-part of the copending applicationof C. E. Staff and W.- N. Stoops, entitled Plastic compositions," SerialNo. 339,490, filed June 8, 1940. That application is concerned withplastic compositions consisting of vinyl resins intimately combined withdiester plasticizers formed by reacting the acidic adducts ofhydrocarbon having conjugated double bonds and maleic acid or anhydride,or their derivatives, with a mono-hydroxyl compound of the groupconsisting of allphatic acyclic and cyclic alcohols having at least sixcarbon atoms, glycol monoethers, and polyglycol monoethers. Thisapplication is concerned with, as new chemical compounds, diesters ofendo-methylene hexahydrophthalic acid with aliphatic acyclic alcoholshaving at least six carbon atoms.

Endo-methylene hexahydrophthalic acid may be obtained by thehydrogenation of the endomethylene tetrahydrophthalic acid which isformed by the addition of cyclopentadiene and malelc anhydride asdescribed in Dlels and Alder Patent No. 1,944,731. The saturated estersmay also be formed by hydrogenation 'of the diesters of endo-methylenetetrahydrophthalic acid with aliphatic acyclic alcohols having at leastsix carbon atoms. Typical higher aliphatic alcohols which may beemployed in forming the new esters are hexanol, 2-ethyl butanol, methylisobutyl carbinol, methyl amyl carbinol, 2-propyl butanol, octanol,Z-ethyl hexanol, lauryl alcohol, undecanol, and stearyl alcohol.

Esterification of the aforesaid endo-methylene hydrophthalic acids withthe foregoing group of higher aliphatic alcohols may be carried out attemperatures ranging from 50 C. to 300 C. and, if desired, in thepresence of suitable catalysts, such as sulfuric acid. The water formedduring esteriflcation may be removed continuously as an azeotropicmixture by distillation with benzene, xylene, or toluene.

The new esters are valuable for various industrial uses. Thus, they maybe used as softeners or modifiers in various waxes and polishes, assoftening agents for leather, and as high boiling solvents, lubricants,textile assistants, and penetrants, but they are particularly suited asplasticizers for vinyl resins.

Viny1 resins from which plastic compositions may be derived bycombination with the new esters are those which may be formed by thepolymerization or condensation of vinyl compounds, such a vinyl acetate,vinyl propionate,

vinyl butyrate, vinyl chloride, vinyl bromide, or

vinyl benzene (styrene). Polyvinyl acetal resins, which may be formed bythe partial or complete reaction of aldehydes with polyvinyl alcohol orincompletely hydrolyzed polyvinyl esters, are also included within thegroup of vinyl resins. A particularly desirable type of vinyl resin foruse in the plastic composition is that which may be formed by theconjoint polymerization of vinyl halides with vinyl ester of aliphaticacids.

The plastic compositions are valuable for various applications and.depending on the use involved, the selection of vinyl resins withspecial characteristics is indicated. If the plastic composition isintended for use in lacquers from which it is deposited, upon drying orbaking, as a protective, ornamental or electrically insulating coatingin the form of a flexible and tough film, the following vinyl resins arepreferred:

a. Polyvinyl acetal resins formed by the condensation of aldehydes withpolyvinyl alcohol.

b. Conjoint polymers of vinyl chloride with vinyl acetate, having anaverage macromolecular weight of from 8,000 to 12,000, and having avinyl chloride content of from to by weight.

If colloidal, homogeneous solid dispersions of the vinyl resins and theplasticizers are to be prepared, the use of highly polymerized,insoluble polyvinyl halides, or of conjoint polymers of vinyl chloridewith vinyl acetate having average macromolecular weights in excess of12,000, and having vinyl chloride contents ranging from 85% to by weightis desirable. Such dispersions are strong and resilient and providehighly serviceable substitutes for leather or for rubber and theirdurable characteristics qualify them for use in cable insulation. Suchdispersions may be prepared by working an amount of the plasticizer fromabout 20% to about 50% by weight of the plastic composition with theresins on a heated rubber mill until a homogeneous colloidal dispersionis obtained.

As contrasted with known plasticizers, such as the lower aliphaticesters of derivatives of tetrahydrophthalic acid, the new esters, whenincorporated in plastic compositions of the type just described, providethe advantages of greater strength at elevated temperatures and ofgreater flexibility at extremely low temperatures of around 15. C. Thislatter effect is unusual in viewpi' the fact that long chain aliphaticradicals in chemical compounds normally tend to Exmrrsl.-Di(2-ethylhea:yl) coda-methylene hexahydrophthalate This ester wasprepared. by heating 900 grams oi endo-methylene hexahydrophthalicanhydride with 1500 grams of Z-ethyl hexanol in the presence of 4 gramsof sulfuric acid. The removal 01 water formed in the reaction wascarried out by an azeotropic distillation in the presence of 200 cc. oitoluene. Thenew ester was recovered as a water-white liquid having aboiling point of 212 C. at 2 mm. It possessed excellent qualities as aplasticizer as shown by the following,

example.

EXAMFLI 2.--Plastic composition Sixty-eight (68) parts by weight of aconjoint polymer of vinyl chloride with vinyl acetate containing about90% by weight vinyl chloride in the polymer and having an averagemolecular weight over 18,000 as determined by Staudingers method, werecombined with 32 parts by weight of di(2-ethy1 hexyl) endo-methylenehexahydrophthalate. A plastic composition having excellent properties ofstrength, toughness and fiexibility was obtained. Thus, its tensilestrength at room temperature was 3490 pounds per square inch and itselongation before rupture was 300%. When parts of highly polymerizedpolyvinyl chloride were combined with 35 parts by weight of the samesaturated ester a plastic composition of similar properties wasobtained. Thus, its tensile strength was 3040 pounds per square inch andits elongation before rupture was I claim.

1. As new chemical compounds, diesters oi endo-methylenehexahydrophthallc acids with aliphatic acyclic alcohols having at leastsix carbon atoms.

2. As new chemical compounds, diesters of.

endo-methylene hexahydrophthalic acid 'with liquid higher fatty alcoholshaving at least six carbon atoms.

3. Di(2-ethylhexyl endo-methylene hexahydrophthalate.

CHARLES E. STAFF.

CERTIQ'FI'CATE 0F CORRECTION. Patent No. 2,511,261. February 16-, 1915.

CHARLES E. STAFF.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page 2,sec- 0ndv column, line 22, after "D1(2-ethylhexy1" insert a.parenthesis; and that the said Letters Patent should be read with thiscorrection therein that the same may conform to the record of,the casein the Patent Office.

Signed and sealed. this 15th day of April, A. D 1915.

I Henry Vet} Arsdale, Acting Conmxiasioner of Patents.

